67 research outputs found
STUDY OF THE IMPACT OF KNOWLEDGE SECTIONS OF ELEMENTARY MATHEMATICS ON THE STUDY OF HIGHER MATHEMATICS IN ENGINEERING UNIVERSITIES
The article presents the results of the study of the impact of knowledge sections of elementary mathematics on the study of higher mathematics by students of Pskov State University. The analysis is based on the knowledge of the elementary mathematics sections tested on a unified state exam (USE). The most important sections of USE's monitoring materials have been identified for the study. The results of these assignments are given to school leavers who have enrolled in 2018 and 2019 at Pskov State University. The regression analysis method examined the impact of USE results on higher mathematics by students studying at the university's technical areas. The regression rate, which indicates the strength of the link between the results of higher and elementary mathematics, is about 40%. Recommendations are made for the organization of the educational process of studying higher mathematics, taking into account the low level of knowledge of school mathematics entering the first year of the universit
ETHNOCONFESSIONAL DISCRIMINATION PHENOMENON IN RUSSIA
The author analyzes forms of discrimination in Russian Federation, which are manifested through extremism, intolerance and xenophobia. The development of this matter is very actual because these problems negatively affect the populations’ mentality. In the author’s opinion, these problems harm the historical basis of Russian nationhood, and scientists should pay more attention to the importance by these facts
Determination of rational steam consumption in steam-air mixture flotation of apatite-nepheline ores
Relevance of the study is determined by the decisions taken to increase the production volume of certain commercial products from mineral raw materials. The scale, impact and consequences of the projects on developing the resource-saving technologies for beneficiation of mineral raw materials are socially significant, and the economic growth of mining production complies with the sustainable development goals. The aim of the study is to develop the flotation circuit and mode that improve the technological performance of beneficiation of apatite-nepheline ores of the Khibiny Massif in the Kola Peninsula. The scientific idea of ​​the work is to develop the flotation circuit, the movement of beneficiation products in which ensures a major increase in the content of the recovered component in the rougher flotation procedure with a simultaneous increase in dressability of the material. The above condition is met when mixing the feedstock with rough concentrate. Recovery of the valuable component from the resulting mixture is accomplished in a mode differing from the known ones in that the heat of steam condensation is used to increase water temperature in the interphase film between the particle and the bubble. For pulp aeration during flotation, a mixture of air and hot steam is used as the gas phase.
A high recovery of the valuable component in ore flotation according to the developed circuit and mode is facilitated by increasing water temperature in wetting films due to the steam condensation heat. A high selectivity of flotation with a steam-air mixture can be explained using the concepts of a phonon component of disjoining pressure, the value and sign of which are associated with a difference in the dynamic structure of liquid in the wetting film and bulk liquid
On the Temporal Effects of Mobile Blockers in Urban Millimeter-Wave Cellular Scenarios
Millimeter-wave (mmWave) propagation is known to be severely affected by the
blockage of the line-of-sight (LoS) path. In contrast to microwave systems, at
shorter mmWave wavelengths such blockage can be caused by human bodies, where
their mobility within environment makes wireless channel alternate between the
blocked and non-blocked LoS states. Following the recent 3GPP requirements on
modeling the dynamic blockage as well as the temporal consistency of the
channel at mmWave frequencies, in this paper a new model for predicting the
state of a user in the presence of mobile blockers for representative 3GPP
scenarios is developed: urban micro cell (UMi) street canyon and
park/stadium/square. It is demonstrated that the blockage effects produce an
alternating renewal process with exponentially distributed non-blocked
intervals, and blocked durations that follow the general distribution. The
following metrics are derived (i) the mean and the fraction of time spent in
blocked/non-blocked state, (ii) the residual blocked/non-blocked time, and
(iii) the time-dependent conditional probability of having blockage/no blockage
at time t1 given that there was blockage/no blockage at time t0. The latter is
a function of the arrival rate (intensity), width, and height of moving
blockers, distance to the mmWave access point (AP), as well as the heights of
the AP and the user device. The proposed model can be used for system-level
characterization of mmWave cellular communication systems. For example, the
optimal height and the maximum coverage radius of the mmWave APs are derived,
while satisfying the required mean data rate constraint. The system-level
simulations corroborate that the use of the proposed method considerably
reduces the modeling complexity.Comment: Accepted, IEEE Transactions on Vehicular Technolog
Physicochemical studies of composite coatings during accelerated tests for atmospheric corrosion
In the present paper, the formation of protective coatings on the MA8 magnesium alloy by plasma electrolytic oxidation (PEO) with subsequent treatment of fluoropolymer is considered. The morphology of coatings after accelerated climatic tests was investigated and the elemental composition of coatings was studied after tests in a salt spray chamber (SSC). The analysis of the obtained results demonstrated a higher corrosion resistance of the fluoropolymer-containing layers in comparison with the base PEO coating
INTERNET PARA OS GANHOS DOS ESTUDANTES: LOCAL DE TRABALHO OU ESPAÇO DE COMUNICAÇÃO
La sobrecarga de trabajo de los docentes puede ocasionar desafÃos para los docentes que provoquen agotamiento a largo plazo si no se abordan. En consecuencia, el presente estudio tiene como objetivo examinar las fuentes de prevención del agotamiento desde las perspectivas de los supervisores EFL (inglés como lengua extranjera). Los participantes fueron 85 supervisores de EFL iranÃes cuyo trabajo consistÃa en observar y dar retroalimentación a los maestros sobre su desempeño docente en varios niveles de dominio del idioma, desde los niveles de primaria hasta los avanzados. En este estudio se empleó un diseño secuencial de método mixto. Primero, la recopilación de datos cualitativos se realizó mediante entrevistas con 30 participantes para determinar las fuentes de prevención del agotamiento desde la perspectiva de los supervisores. A continuación, se diseñó un cuestionario de prevención de agotamiento utilizando los resultados de las entrevistas, después de lo cual se administró a los participantes restantes. Los datos recopilados fueron analizados por factores para identificar los componentes de la construcción de prevención de agotamiento. Los resultados del análisis de contenido de los datos de la entrevista indicaron que el apoyo de los maestros por parte de sus colegas, la situación menos estresante y la satisfacción laboral fueron las principales fuentes de prevención del agotamiento. El análisis factorial mostró las mismas fuentes de agotamiento que los componentes principales de la construcción de prevención de agotamiento. Los hallazgos de este estudio enfatizan la contribución del apoyo educativo y emocional de los maestros, proporcionando un lugar de trabajo constructivo y saludable, asà como ingresos deseables como formas de prevención del agotamiento en los maestros de EFL.Teacher work overload can cause challenges for teachers leading to burnout in the long term if not addressed. Consequently, the present study aims at examining the sources of burnout prevention from EFL (English as a foreign Language) supervisors’ perspectives. The participants were 85 Iranian EFL supervisors whose job was observing and giving feedback to teachers about their teaching performance at various levels of language proficiencies from elementary to advanced levels. A sequential mixed method design was employed in this study. First, collection of qualitative data was performed using interviews with 30 participants in order to determine the sources of burnout prevention from supervisors’ perspectives. Next, a burnout prevention questionnaire was designed using the results of the interviews, after which it was administered to the remaining participants. The collected data were factor analyzed to identify the components of burnout prevention construct. Results of content analysis of the interview data indicated that teachers’ support from their colleagues, less stressful situation, and job satisfaction were the main sources of burnout prevention. Factor analysis showed the same sources of burnout as the main components of the burnout prevention construct. The findings of this study emphasize on the contribution of teachers’ educational and emotional support, providing constructive and healthy working place, as well as desirable income as ways for prevention of burnout in EFL teachers.A sobrecarga de trabalho do professor pode causar desafios para os professores, levando a esgotamento a longo prazo, se não forem abordados. Consequentemente, o presente estudo tem como objetivo examinar as fontes de prevenção de burnout das perspectivas dos supervisores de EFL (inglês como lÃngua estrangeira). Os participantes foram 85 supervisores iranianos de EFL, cujo trabalho era observar e dar feedback aos professores sobre seu desempenho no ensino em vários nÃveis de proficiência linguÃstica, do nÃvel básico ao avançado. Um método misto sequencial foi empregado neste estudo. Primeiro, a coleta de dados qualitativos foi realizada por meio de entrevistas com 30 participantes, a fim de determinar as fontes de prevenção de burnout na perspectiva dos supervisores. Em seguida, foi elaborado um questionário de prevenção de burnout, utilizando os resultados das entrevistas, após o qual foi aplicado aos demais participantes. Os dados coletados foram analisados por fatores para identificar os componentes do construto de prevenção de burnout. Os resultados da análise de conteúdo dos dados da entrevista indicaram que o apoio dos professores de seus colegas, a situação menos estressante e a satisfação no trabalho foram as principais fontes de prevenção de burnout. A análise fatorial mostrou as mesmas fontes de burnout que os principais componentes do construto de prevenção de burnout. As conclusões deste estudo enfatizam a contribuição do apoio educacional e emocional dos professores, proporcionando um local de trabalho construtivo e saudável, bem como a renda desejável como formas de prevenção do esgotamento nos professores de EFL
Aerial Access and Backhaul in mmWave B5G Systems: Performance Dynamics and Optimization
The use of unmanned aerial vehicle (UAV)-based communication in
millimeter-wave (mmWave) frequencies to provide on-demand radio access is a
promising approach to improve capacity and coverage in beyond-5G (B5G) systems.
There are several design aspects to be addressed when optimizing for the
deployment of such UAV base stations. As traffic demand of mobile users varies
across time and space, dynamic algorithms that correspondingly adjust the UAV
locations are essential to maximize performance. In addition to careful
tracking of spatio-temporal user/traffic activity, such optimization needs to
account for realistic backhaul constraints. In this work, we first review the
latest 3GPP activities behind integrated access and backhaul system design,
support for UAV base stations, and mmWave radio relaying functionality. We then
compare static and mobile UAV-based communication options under practical
assumptions on the mmWave system layout, mobility and clusterization of users,
antenna array geometry, and dynamic backhauling. We demonstrate that leveraging
the UAV mobility to serve moving users may improve the overall system
performance even in the presence of backhaul capacity limitations.Comment: 7 pages, 5 figures. This work has been accepted to IEEE
Communications Magazine, 201
Electrical Spinal Stimulation, and Imagining of Lower Limb Movements to Modulate Brain-Spinal Connectomes That Control Locomotor-Like Behavior
Neuronal control of stepping movement in healthy human is based on integration between brain, spinal neuronal networks, and sensory signals. It is generally recognized that there are continuously occurring adjustments in the physiological states of supraspinal centers during all routines movements. For example, visual as well as all other sources of information regarding the subject's environment. These multimodal inputs to the brain normally play an important role in providing a feedforward source of control. We propose that the brain routinely uses these continuously updated assessments of the environment to provide additional feedforward messages to the spinal networks, which provides a synergistic feedforwardness for the brain and spinal cord. We tested this hypothesis in 8 non-injured individuals placed in gravity neutral position with the lower limbs extended beyond the edge of the table, but supported vertically, to facilitate rhythmic stepping. The experiment was performed while visualizing on the monitor a stick figure mimicking bilateral stepping or being motionless. Non-invasive electrical stimulation was used to neuromodulate a wide range of excitabilities of the lumbosacral spinal segments that would trigger rhythmic stepping movements. We observed that at the same intensity level of transcutaneous electrical spinal cord stimulation (tSCS), the presence or absence of visualizing a stepping-like movement of a stick figure immediately initiated or terminated the tSCS-induced rhythmic stepping motion, respectively. We also demonstrated that during both voluntary and imagined stepping, the motor potentials in leg muscles were facilitated when evoked cortically, using transcranial magnetic stimulation (TMS), and inhibited when evoked spinally, using tSCS. These data suggest that the ongoing assessment of the environment within the supraspinal centers that play a role in planning a movement can routinely modulate the physiological state of spinal networks that further facilitates a synergistic neuromodulation of the brain and spinal cord in preparing for movements
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